Bicycle handlebar brake lighting

Arduino Bikes Fun & Games

MAKE subscriber Justin Shaw has posted a project on Instructables for a bike brake lighting system that features lights on the ends of a bicycle’s handlebars, controlled by an Arduino and a Pololu 3-axis accelerometer. He’s even offering a $35 prize to the first person who follows his plans and posts proof of a successful build.

Bar End Brake Light: BEBL

14 thoughts on “Bicycle handlebar brake lighting

  1. Shadyman says:

    Bonus points if you add a yellow LED for nighttime travel.. even more if you add turn signals based on accelerometer input.

  2. japroach says:


    shady: sadly a turn signal is useless unless its manually controlled.

  3. Angus Og says:

    Well it’s a neat idea but in reality, what use is brake light on a bike? How is it any more useful than a flashing or steady red light? At bicycle speeds an indication of braking is not really of any use to other road users.

    Also, a cheaper and more robust implementation would be a simple switching mechanism at the brake levers.

  4. BusterB says:

    In addition to the ‘robust’ comment – exactly how is someone, presumably a driver in a vehicle, supposed to see these lights? It is fine if one is at an oblique angle, but even directly behind a near-anorexic woman the lights are obstructed. So of what use are the lights?

    And of what use are the lights in bright daylight? Useful, or useless?

    1. Marc says:

      @BusterB: I think that is his young daughter, not an near anorexic woman.

      I don’t think this supposed to be a perfect and final solution. Looking at his blog, it is one in a line of iterations over bike light & brake light designs as well as general arduino tinkering. For instance, check out his uber light:

      This form factor does have one bonus, you can plug those into the handlebars without any addition to the bike or modification to the braking mechanism.

  5. Anonymous says:

    That music R to L fade was annoying!

  6. doroti says:

    “At bicycle speeds an indication of braking is not really of any use to other road users.”

    … so cars going 30mph don’t need to signal stopping either then? Sorry that’s just wrong. I can go 45 mph on big downhills and I’m just a commuter, not a racer. Realistically I often do 30 on mild slopes and this is occasionally necessary to beat traffic for a short stretch. On flats I typically cruise at 18mph. Amazingly drivers often have no regard for life and will actually tail gate a cyclist at such speed. I can stop very fast. I really like this idea. Some kind of water spray out the back would be nice too.. may. Drivers wrong preconception that bikes move at a crawl is a huge cause of dangerous situations usually involving being cutoff.

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Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. His free weekly-ish maker tips newsletter can be found at

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